void main() {
  Person p1 = Person("八戒", 100);
  print(p1.age);
  print(p1.name);
}

class Person {
  String? name;
  num age = 100;
  // Person(String name, num age) {
  //   this.name = name;
  //   this.age = age;
  // }

  //以上构造函数和传递参数的简写
  Person(this.name, this.age);
}
